Foreach loop

<p>In <a href="/facts/Computer_programming/QmSsFnu0">computer programming</a>, foreach loop (or for-each loop) is a <a href="/facts/Control_flow/2XTDfErC">control flow</a> statement for traversing items in a <a href="/facts/Collection_class/gsC5UcqD">collection</a>. foreach is usually used in place of a standard <a href="/facts/For_loop/cwV2nRzp">for</a> loop <a href="/facts/Statement_(computer_science)/bEkBufqX">statement</a>. Unlike other for loop constructs, however, foreach loops usually maintain no explicit counter: they essentially say "do this to everything in this set", rather than "do this x times". This avoids potential <a href="/facts/Off-by-one_error/2rMj4LYM">off-by-one errors</a> and makes code simpler to read. In <a href="/facts/Object-oriented/TxNMEcao">object-oriented</a> languages, an <a href="/facts/Iterator/f0HhTBWz">iterator</a>, even if implicit, is often used as the means of traversal.
</p><p>The foreach statement in some languages has some defined order, processing each item in the collection from the first to the last.
The foreach statement in many other languages, especially <a href="/facts/Array_programming/gFx1SxIY">array programming</a> languages, does not have any particular order. This simplifies <a href="/facts/Loop_optimization/2eFKIg32">loop optimization</a> in general and in particular allows <a href="/facts/Vector_processing/nYAsIKT0">vector processing</a> of items in the collection concurrently.
</p>

Foreach loop open-in-new

Foreach loop